From: Yo'av Moshe <linux@yoavmoshe.com>
To: Frank Li <Frank.Li@nxp.com>,
Sascha Hauer <s.hauer@pengutronix.de>,
Russell King <linux@armlinux.org.uk>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>,
Fabio Estevam <festevam@gmail.com>,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Bill Wendling <morbo@google.com>,
Justin Stitt <justinstitt@google.com>,
imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
llvm@lists.linux.dev, stable@vger.kernel.org,
linux-kernel@vger.kernel.org, Yo'av Moshe <linux@yoavmoshe.com>
Subject: [PATCH v2] ARM: imx: Fix suspend/resume crash with Clang CFI
Date: Sat, 18 Jul 2026 11:19:17 +0200 [thread overview]
Message-ID: <20260718091917.81738-1-linux@yoavmoshe.com> (raw)
Relocated suspend code in OCRAM lacks compiler-generated CFI type
signatures. When CONFIG_CFI=y is active, the indirect call to
imx6_suspend_in_ocram_fn triggers a strict CFI violation panic.
Annotate imx6q_suspend_finish with __nocfi to bypass CFI checking
for this specific indirect call.
Additionally, protect the imx6_suspend_in_ocram_fn pointer by marking
it __ro_after_init to prevent it from being used as a CFI bypass
exploit vector.
Cc: stable@vger.kernel.org
Signed-off-by: Yo'av Moshe <linux@yoavmoshe.com>
---
Tested on a Kobo Clara HD (i.MX6SLL SoC) running postmarketOS edge.
Before this patch, suspending the device caused an immediate silent
hang requiring a hard-reboot. With this patch applied, suspend and
resume work successfully.
Differences from v1:
- Added __ro_after_init to imx6_suspend_in_ocram_fn to prevent it
from being exploited as a CFI bypass gadget.
arch/arm/mach-imx/pm-imx6.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm/mach-imx/pm-imx6.c b/arch/arm/mach-imx/pm-imx6.c
index a671ca498..b425a4701 100644
--- a/arch/arm/mach-imx/pm-imx6.c
+++ b/arch/arm/mach-imx/pm-imx6.c
@@ -63,7 +63,7 @@
static void __iomem *ccm_base;
static void __iomem *suspend_ocram_base;
-static void (*imx6_suspend_in_ocram_fn)(void __iomem *ocram_vbase);
+static void (*imx6_suspend_in_ocram_fn)(void __iomem *ocram_vbase) __ro_after_init;
/*
* suspend ocram space layout:
@@ -360,7 +360,7 @@ int imx6_set_lpm(enum mxc_cpu_pwr_mode mode)
return 0;
}
-static int imx6q_suspend_finish(unsigned long val)
+static int __nocfi imx6q_suspend_finish(unsigned long val)
{
if (!imx6_suspend_in_ocram_fn) {
cpu_do_idle();
--
2.55.0
reply other threads:[~2026-07-18 9:20 UTC|newest]
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